CVE-2026-44636
Published: 14 May 2026
Summary
CVE-2026-44636 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability. Its CVSS base score is 7.4 (High).
Operationally, it is not currently listed in the CISA KEV catalog.
NVD Description
libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. From to 1.8.7-r1, signed integer overflow in sixel_encode_highcolor's allocation size calculation can lead to a heap buffer overflow. The public sixel_encode entry point validates only that width and height are…
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greater than zero, with no upper bound. width and height are multiplied as plain int when computing the allocation size for paletted_pixels and normalized_pixels. Any caller that asks libsixel to encode a pixel buffer with width times height greater than INT_MAX (about 2.15 billion) will hit a wrapped allocation size; under the right wrap, the malloc succeeds with a buffer much smaller than the encoder expects, and the encoder writes past the end of the heap allocation. This vulnerability is fixed in 1.8.7-r2.
Deeper analysisAI
Automated synthesis unavailable for this CVE.
Details
- CWE(s)